Trait CheckedNeg 

pub trait CheckedNeg: Sized {
    type Output;

    // Required method
    fn checked_neg(self) -> Option<Self::Output>;
}

Performs negation, returning None if the result can’t be represented.

Required Associated Types

type Output

The negation result type (Self for the primitive impls; a distinct owned type lets non-Copy types implement this for references).

Required Methods

fn checked_neg(self) -> Option<Self::Output>

Negates a number, returning None for results that can’t be represented, like signed MIN values that can’t be positive, or non-zero unsigned values that can’t be negative.

Examples

use const_num_traits::CheckedNeg;
use std::i32::MIN;

assert_eq!(CheckedNeg::checked_neg(1_i32), Some(-1));
assert_eq!(CheckedNeg::checked_neg(-1_i32), Some(1));
assert_eq!(CheckedNeg::checked_neg(MIN), None);

assert_eq!(CheckedNeg::checked_neg(0_u32), Some(0));
assert_eq!(CheckedNeg::checked_neg(1_u32), None);

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

impl CheckedNeg for i8

type Output = i8

fn checked_neg(self) -> Option<i8>

impl CheckedNeg for i16

type Output = i16

fn checked_neg(self) -> Option<i16>

impl CheckedNeg for i32

type Output = i32

fn checked_neg(self) -> Option<i32>

impl CheckedNeg for i64

type Output = i64

fn checked_neg(self) -> Option<i64>

impl CheckedNeg for i128

type Output = i128

fn checked_neg(self) -> Option<i128>

impl CheckedNeg for isize

type Output = isize

fn checked_neg(self) -> Option<isize>

impl CheckedNeg for u8

type Output = u8

fn checked_neg(self) -> Option<u8>

impl CheckedNeg for u16

type Output = u16

fn checked_neg(self) -> Option<u16>

impl CheckedNeg for u32

type Output = u32

fn checked_neg(self) -> Option<u32>

impl CheckedNeg for u64

type Output = u64

fn checked_neg(self) -> Option<u64>

impl CheckedNeg for u128

type Output = u128

fn checked_neg(self) -> Option<u128>

impl CheckedNeg for usize

type Output = usize

fn checked_neg(self) -> Option<usize>

Implementors